IWC (the initials stand for International Watch Company) has its earthbound roots in Switzerland, where it was founded in 1868 by a Boston watchmaker memorably named Florentine Ariosto Jones. By 1936 the company's timepieces were aloft on pilots' arms, and aviation watches still figure prominently in the product line, whose imagery is centered on sports, flight and exploration, with an overlay of celebrity.

Richemont, which bought IWC in 2000, brought in a young German, Georges Kern, to run it, and Kern has enlisted some boldface acquaintances (Cate Blanchett, Ewan McGregor, Kevin Spacey) to support the brand. His latest coup: Jeremy Renner sports an IWC in The Bourne Legacy .

IWC has also engaged in a campaign of product launches, at price points from $4,500 to $300,000. But the high-flying company also began an R;&D program that would take its top watches, in effect, out of Earth's orbit altogether.

The Portuguese Sid?rale Scafusia pictured here was a decade in the making, combining a giant tourbillon, a perpetual calendar and a celestial chart. The chart display on the back (pictured, right) tells sidereal (astronomical) time. Each chart can be customized to the customer's constellations and coordinates of choice. Says Kern, "The combination of solar time and sidereal time in the same watch was certainly not the idea initially, but it is a clear indication that unusual things take time." Indeed they do?if you want one of the $750,000 pieces, you'll have time on your hands before you have it on your wrist: The watch requires a year for delivery. ? PAIGE REDDINGER

Zenith Christophe Colomb Equation of Time ($244,000)

This claims to be the world's first wristwatch with a rate of vibration independent of its wearer's movements?its regulating system is mounted on a gyroscope within a sapphire crystal dome.

Breguet Equation of Time ($180,900)

This ultra-elegant watch packs a patented equation of time function?displaying the difference between manmade mean and "natural" time?and a calendar, both accurate for the next 99 years.

Vacheron Constantin Patrimonie Traditionnelle Calibre 2253 ($464,000)

A tourbillon with an eye toward the sky, displaying the equation of time, sunrise and sunset, and a 100-year perpetual calendar, all with a 336-hour power reserve.

Audemars Piguet Royal Oak Equation of Time ($130,600)

Equipped with sunrise and sunset times, astronomical moon, and a perpetual calendar?all combined with the world's thinnest self-winding movement with a mechanical rotor.

Panerai L'Astronomo ($223,200)

An astonishing watch that packages an array of complications. It's Panerai's most complicated watch ever and includes a shifting map of the night sky on its back tailored to each client's preferred location.